2018–2023 GMC Terrain · common problems & known faults

1.5T carbon build-up / oil consumption.

Typically appears

60,000+ miles

What to inspect

Check oil level and watch for rough idle.

9-speed shudder and shift-to-park glitch.

Typically appears

Any

What to inspect

Feel for shudder and confirm clean park engagement.

AC condenser faults.

Typically appears

70,000+ miles

What to inspect

Confirm cold AC output.

Stabilitrak / infotainment glitches.

Typically appears

Age-related

What to inspect

Watch for warnings and test the screen.

Hard brake pedal and reduced braking assistance due to mechanical vacuum pump failure on 1.5T models.

Typically appears

40,000-70,000 miles

What to inspect

Start the engine and pump the brake pedal rapidly three to four times. If the pedal becomes rock hard and fails to regain vacuum assistance within a few seconds, the pump is failing.

Water ingress into the cabin caused by blocked or detached panoramic sunroof drain tubes.

Typically appears

3-5 years

What to inspect

Press firmly into the front footwell carpets to feel for dampness. Open the sunroof and check the front corner drain channels for standing water, silt, or leaf debris.

Creaking, popping, or binding noises from the front end caused by premature wear of the MacPherson strut top mounts and bearings.

Typically appears

30,000-60,000 miles

What to inspect

With the vehicle stationary and engine idling, turn the steering wheel fully from lock to lock. Listen closely outside the front windows for a distinct spring-binding or popping noise.

Power boot fails to open fully, groans during operation, or sags downwards due to failing spindle drive struts.

Typically appears

50,000-80,000 miles

What to inspect

Open the boot using the key fob. Ensure it travels smoothly to its maximum height without groaning. Apply light downward pressure to the open tailgate; it should hold firm without collapsing.